[PATCH 5.17 0528/1126] libbpf: Fix signedness bug in btf_dump_array_data()

Greg Kroah-Hartman
2022-04-05T08:21:58Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 4172843ed4a38f97084032f74f07b2037b5da3a6 ]

The btf__resolve_size() function returns negative error codes so
"elem_size" must be signed for the error handling to work.

Fixes: 920d16af9b42 ("libbpf: BTF dumper support for typed data")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220208071552.GB10495@kili
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/lib/bpf/btf_dump.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index b9a3260c83cb..55aed9e398c3 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1861,14 +1861,15 @@ static int btf_dump_array_data(struct btf_dump *d,
{
const struct btf_array *array = btf_array(t);
const struct btf_type *elem_type;
- __u32 i, elem_size = 0, elem_type_id;
+ __u32 i, elem_type_id;
+ __s64 elem_size;
bool is_array_member;

elem_type_id = array->type;
elem_type = skip_mods_and_typedefs(d->btf, elem_type_id, NULL);
elem_size = btf__resolve_size(d->btf, elem_type_id);
if (elem_size <= 0) {
- pr_warn("unexpected elem size %d for array type [%u]\n", elem_size, id);
+ pr_warn("unexpected elem size %lld for array type [%u]\n", elem_size, id);
return -EINVAL;
}

--
2.34.1